The following is a compare between the old default interface (4.29.13) and the new default interface patched GU66 today (4.30.13) on the right with changes in red. Use the context & line numbers to help find your way to make the changes needed to your custom interface.

Didn't quite look at every single file due to not using them all, but the biggest changes I've found so far is a new AutoAssist button for the Pet window, and a new tab for the Journal called DailyObjectives

*Edit* And some new House bar stuff, but I don't have edit for that, just thought I'd note the additions.

Yeah, main changes I saw were autoassist toggle button in the pet window & pet options window popup, the new DailyObjectives thing (I'm guessing that's not functional yet? I don't remember seeing it in the final patch notes), save/load buttons on the community (friends) window, and various things related to the house editing wheel / controls. IIRC there was something else in the marketplace window as well, probably support for the delayed player studio house sales.

The vast majority of changes to the edited files are just them changing localization tags and, more than anything, removing PackSizeProp parameters from things.

/pet attack and /pet backoff seem to have been removed. Any chance of investigating slash command changes?

Do you mean the actual / commands have been removed? If so, your best bet would be to try and poke Terrogaunt on the official forums, he's the only one I've seen doing UI things lately. It's a bit odd that they'd take them out tho.

Do you mean the actual / commands have been removed? If so, your best bet would be to try and poke Terrogaunt on the official forums, he's the only one I've seen doing UI things lately. It's a bit odd that they'd take them out tho.

I've got a macroed attack button that uses /pet attack, and now when I use this command, here's what happens:

(1367375910)[Tue Apr 30 21:38:30 2013] Your pet does not know how to do that command.
(1367375910)[Tue Apr 30 21:38:30 2013] You send your pet in for the attack!

When I cast a new pet, the pet summoning spell is in a macro with /pet backoff. It is likewise not behaving, and I get the same message.

(1367375910)[Tue Apr 30 21:38:30 2013] Your pet does not know how to do that command.
(1367375910)[Tue Apr 30 21:38:30 2013] You send your pet in for the attack!

Update: Word is that the game is seeing my deity pet as well as the regular conjy pet, and trying to apply pet commands to the deity pet inappropriately. Apparently other types of non-combat pets can cause this issue as well. They're supposed to fix that Real Soon Now.